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Aiming at the problems in positioning accuracy of stereo vision guided robots. Here, we firstly calibrated two cameras separately and calculated the relative position-attitude between the two cameras. A more accurate relative position-attitude and the distortion parameters between the two cameras of each image were obtained by optimizing the projection error of the marks via Bundle Adjustment (BA). Then, we identified the world coordinates of the marker point by using the triangulation principle of the parallel binocular camera. According to the position-and-pose parameters of each image that captured by left camera and the data of corresponding robot end, Tsai hand-eye calibration method was applied to work out the relative position-and-attitude of the end of the robot to the left camera. Hence, the robot could be accurately guided to operate with the precise position of target point. The experimental result suggests that the algorithm in this study is favorably reasonable and can accurately to guide robot positioning.

The dual active bridge (DAB) DC-DC converter plays an important role in the ship integrated power system energy storage device. To improve its dynamic characteristics in the case of fluctuations at the input and output ends, a new control strategy is proposed. The strategy is based on direct power control (DPC) which obtains the transmission power deduced from the single phase shift control and the virtual current is introduced to amend it. This strategy eliminates the need for device parameters to participate in the control and only samples the input and output voltages which significantly simplifies the controller structure and improves its compatibility. The proposed strategy and traditional PI control are compared and simulated through the simulation model built in PSCAD. The results show that the proposed strategy can effectively improve the dynamic performance of the DAB DC-DC converter.

The energy management system (EMS) is an important part of vessel integrated power system (IPS). Its performance significantly effects the overall performance of the IPS. The EMS usually adopts a hybrid information network structure featured by a hierarchical topology and adoption of multiple network protocols. In this paper, a double-layer hybrid information network consisting of Ethernet and CAN bus is taken as the research object. In OPNET Modeler, node models of CAN bus terminal, CAN subnet controller, Ethernet data module and Ethernet controller are built, and the simulation model of the hybrid EMS network is constructed. Transmission delay of data packets is analyzed under different network topologies and circumstances. The models are validated through simulation results, and the proposed modeling method can provide theoretical basis and simulative method for the design and implementation of future IPS EMS information network.

A piecewise linearized power distribution control strategy of Hybrid Energy Storage System (HESS) for the DC vessel microgrid is proposed in this paper. It not only can stabilize the DC bus voltage well but also can optimize the charge/discharge operation of storage units according to their current state-of-charge (SOC) level. The high power density energy storages (e.g. supercapacitor) response quickly to compensate the instantaneous load variation and keep the bus voltage stabilization, the high energy density energy storages (e.g. lithium battery) supply the continuous energy, moreover, the charge/discharge power of the lithium battery is closely related to the current SOC level of the supercapacitor. Simulation results indicate that the control strategy can automatically adjust the working state and output of the supercapacitor and lithium battery, and maintain the DC bus voltage within a reasonable range when the load demand suddenly change.

Stand-alone microgrid system consist of hybrid wind/PV/diesel/storage is one of the effective approaches to solve the problem for future island power supply while plan and design are one of the core technical systems of it. According to operation requirements of the island stand-alone microgrid and the characteristics of distributed power supply as well as the optimization demand of microgrid capacity, an optimized scheduling model for microgrid that consider the initial investment cost, maintenance and replacement cost, fuel cost, environmental management cost, and power shortage penalty cost is proposed in this paper. The constraint of the utilization rate of renewable energy, single and total loss of power supply probability (LPSP), single and total dumped energy proportion (DEP) are also under consideration. Through the establishment of the mixed integer linear programming model (MILP), the integrated modeling and solving of the stand-alone microgrid planning and optimization scheduling problem are realized. The effectiveness of the designed model is verified through the result of some island microgrid. Furthermore, the impact of the reliability constraint of the system power supply and the penalty factor of the dumped wind/PV energy is analyzed.

In order to reduce the negative effect of lower-temperature water released from the intake to the environment in the downstream reach, a selective withdrawal structure will adopted in Glen Canyon Dam. The 3D numerical model EFDC was used to simulate the velocity fields and water temperatures released with surface and lower withdrawal. The numerical results of water temperature released are validated with the measured data. The velocity fields with surface and lower withdrawal indicate that the mainstream of withdrawal water column is located near the elevation of withdrawal intake. Temperatures of water released from the surface and lower withdrawal are simulated for twelve months. The temperatures of water released with a surface withdrawal are effectively enhanced compared with the lower withdrawal.